Sound is the movement of energy through substances in longitudinal (compression/rarefaction) waves.

A sound is produced when a force causes an object or substance to vibrate — the energy is transferred through the substance in a wave. Typically, the energy in sound is far less than other forms of energy.

Let’s consider this illustration.

A vibrating drum from a band drummer transfers energy to the audience as sound. Kinetic energy from the moving air molecules transfers the sound energy to the audience’s eardrums. Notice that Kinetic (movement) energy in the sticks is being transferred into sound energy.

Sound vibrations create sound waves that move through mediums such as air and water before reaching our ears.

The diagram below shows how a sound wave is represented:

Sound energy is usually measured by its pressure and intensity, in special units called pascals and decibels. Sometimes, loud noise can cause pain to people. This is called the threshold of pain. This threshold is different from person to person. For example, teens can handle a lot of higher sound pressure than the elderly, or people who work in factories tend to have a higher threshold pressure because they get used to loud noise in the factories.from a ddddd